These studies utilize neuroendocrine tests of hypothalamic-pituitary function to increase our understanding of the central nervous system effects of anti-depressant drugs. The effects of apomorphine, L-Dopa, arginine and insulin on plasma prolactin, growth hormone, cortisol, norepinephrine, and dopamine beta hydroxylase were studied in depressed patients treatment with lithium carbonate. The effects of L-tryptophan on plasma prolactin, growth hormone, cortisol, norepinephrine and dopamine beta hydroxylase were studied in depressed patients The effects of two monoamine oxidase inhibitors (MAOI), clorgyline and pargyline, on plasma cortisol and prolactin were studied in depressed patients during a pretreatment period and again during treatment with each MAOI. Cortisol levels were not significantly changed by either MAOI. Prolactin levels were significantly elevated by both MAOI's, with every individual studied demonstrating an increase. BIBLIOGRAPHIC REFERENCES: Slater, S., de la Vega, C.E., Skyler, J., and Murphy, D.L.: Plasma prolactin stimulation by fenfluramine and amphetamine. Psychopharmacol. Bull. 12: 26-27, 1976. Slater, S.L., Lipper, S., Shiling, D.J. and Murphy, D.L.: Monoamine oxidase inhibitors elevate plasma prolactin in man. Lancet, 1977, in press.